Herbicide



Patented Dec. 23, 1952 UNITED STATES PATENT OFFICE HERBICIDE No Drawing. Application June 30, 1950, Serial No. 171,572

1 Claim.

This invention relates to herbicides and has for its object the provision of an improved plant regulant composition having pronounced herbicidal properties and an improved method of killing or suppressing the growth of plants. The invention provides compositions comprising certain undecylenates and chloroacetic acid.

This invention is based upon our discovery that undecylenic acid and halogenated undecylcnic acid, their salts, esters and amides and the corresponding aldehydes which oxidize readily to such acids, are herbicides which kill many plants including most common weeds when applied to the foliage as sprays, especially in aqueous sprays, for example, in concentrations of from 0.3% to The following undecylenates are especially effective herbicides: Undecylenic acid, methyl undecylenate, isobutyl undecylenamide, n-undecylenic aldehyde, brominated undecylenic acid, and polyethylene glycol (300) mono-undecylenate.

The undecylenates are derived from undecylenic acid, a relatively inexpensive compound which may be produced in various ways, notably as a fraction of castor oil. The compounds are relatively insoluble in water but may be dispersed in water with suitable solubilizers and emulsifiers. Suitable compositions comprising the compounds dispersed in water may be prepared by adding, for example, solvesso 100 oil, Cellosolve, and Emulior Ela, to the compounds and diluting with water. The results of the application of aqueous spray compositions of undecylenic acid in various concentrations to many weeds and crop plants are illustrated in Table I. Our application Serial No. 171,574, filed June 30, 1950, covers a method of using undecylenates for herbicidal urposes.

Chloroaeetic acid is not only an effective plant regulant but it has commercial and practical advantages because of its availability, low cost,

and relatively high solubility in water. One of the unexpected and important characteristics of chloroacetic acid is that it can be readily taken up by one part of the plant and translocated to another part. If taken up by the roots, the chemical goes into the plant and kills the top of the plant. If applied to the top of the plant, it will migrate to the roots where eventually the Whole plant may be killed.

Chloroacetic acid has plant regulant properties when applied to various plants in concentrations from 0.10% to 10%. At concentrations of 0.3% to 10% the compound functions as a general herbicide, while at lower concentrations (0.3% to 3%) it functions as a selective herbicide whereby many common weeds may be killed entirely or partly without causing noticeable injury to certain crop plants such as corn, potatoes, grasses, gladioli, and the like. The results of using aqueous spray solutions of chloroacetic acid on common weeds and crop plants are shown in the tests of Table II. These tests show that sprays containing around 0.1% of the acid had no effect on either weeds or crop plants. Some plants could be killed with 1% solutions, while others required up to 10%. For complete killing, solutions containing less than 1% were not effective. When applied at the rate of 20 to 40 pounds per acre as a pre-emergence spray to soil, chloroacetic acid kills young weeds without causing injury to corn planted just before the spray is applied. Buds of potato tubers may be inhibited or killed without noticeable injury to the tuber. The effectiveness of soil applications of chloroacetic acid in killing young tomato plants (screening test) is illustrated in Table III. Our application Serial No. 171,573, filed June 30, 1950, covers a method of using chloroacetic acid for herbicidal purposes.

When an undecylenate, for example undec'ylenic acid, and chloroacetic acid are used conjointly or in combination in the same spraying medium, the effect is more pronounced than the sum of the separate effects of the compounds. The tests of Table IV show either synergism or mutual activation in the greatly intensified killing action.

One explanation is that the intensified action is due to the activating effect the compounds exercise on each other. Regardless of the explanation of the cause of the improved result, the composition gives results not attainable with either compound used alone in comparable amounts. For example, chloroacetic acid is selective in its action in the killing of different kinds of plants. Undecylenic acid does not kill grasses in relatively low concentrations but in proper dosage will kill crabgrass without noticeable injury to lawn grasses. For example, crabgrass plants can be killed in late May and June Without noticeable injury to Kentucky blue grass. However, the composition at relatively low concentrations is an efiective killer of grasses.

3 The tests of the tables were carried out on greenhouse plants. The same tests were carried out on plants in the field with surprisingly better results.

TABLE I Minimum percentage concentrations of undecylenic acid sprays effective for inducing the responses indicated 4 the flowers or young set fruit (calyx stage) to effect blossom or fruit thinning. They may be applied, for example, to potato vines just before harvesting to kill the vines, without injury to the tubers.

We have found that chloropicrin increases the herbicidal properties of the composition causing a further intensified action. The effect is synergistic and enables the concentrations of the compounds to be reduced without a diminishing Column Numbr effect on the plants. Moreover, the chloropicrin has a pronounced herbicidal action on plants of 1 2 3 4 5 a low order such as fungi, particularly soil-borne Species fungl.

Severe Slight ptlete foliage 'foliage Noin1" 0 'ur' ii'iiiillg kiiitig a 1 3 TABLE 11 Weeds: Minimum concentrations of chloroacetic acid Clover 1.0 1.0 032 0.3 0 1 20 (.CHzClCOOH) sprays effective for inducing Chickwecd 3.2 1.0 032 0.32 0.1 0mm U m L0 Q32 01 0,032 the responses indicated. Entire plant sprayed (alinsoga 3.2 1.0 0.32 0.32 0.32 1 h i 1'C1I1818I1fl1US 1.0 1.0 0.32 0. 32 0.32 un 683 ct em 6 noted GhcnopodiunL. 1.0 1.0 0.32 0. 32 0.1 Smartweed 3. 2 3. 2 1. 0 0.3 0.1 'lurslane. 1. O 1. 0 0. 32 0. 32 0. 32 Column Number Crab grass 3. 2 1.0 0.32 0. 32 0. 32 Water hyacinth 3. 2 3. 2 1.0 l. 0 1. 0 Alligator weed. 3.2 3.2 1.0 1.0 1.0 1 2 3 i 3 Wild carrot 1.0 1.0 0.32 032 0.32 S Alglae 1.0 1.0 1.0 1.-0 1.0 pews Crop ants: Com- Com- Tomato 1.0 1.0 0.32 0. 32 0.1 plete plete 2 811g) Noin- 3.2 3.2 0.32 0. 0.032 in plant top P P 1 jury 3.2 3.2 1.0 1.0 1.0 killing killing mil"? 3.2 3.2 1.0 1.0 1.0 32 3.2 3.2 1.0 1.0 3.2 32 1.0 1.0 1.0 Weeds: 1.0 1.0 1.0 1.0 1.0 Amal'anthus 1.0 1.0 0.32 0.1 0.1 1.0 1.0 1.0 1.0 1.0 0110110 000101 1.0 1.0 0.32 01 01 1.0 1.0 1.0 1.0 1.0 Cllickweed 1.0 1.0 0.32 0.1 0.1 1.0 1.0 1.0 1.0 1.0 Clover 1.0 1.0 0.32 01 01 3.2 1.0 0.32 0.1 0.032 Crab grass 1. 3.2 3.2 1.0 0.32 0.1 Barley 3.2 1.0 0.32 0.32 0 1 Galinsoga 1.0 1.0 0.32 0.1 0.1 Buckwheat .1 3.2 1.0 1.0 0-32 0- OXaliS 1.0 1.0 0.32 0.1 0.1 Purslane 1.0 1.0 0.32 0.l 0.1 1 Smartweed 1.0 1.0 0.32 0.l 0.1 Nora.-Apparently not trnnslocatcd. Wild carrot 1.0 1.0 0.32 0.l 0.1 f onsidered tolerant. 40 Waterhyaeinth. 10.0 3.2 1.0 0. 32 0.1 Alllgatorwced 100 10.0 3.2 1.0 1.0 Algae 10.0 10.0 1.0 1.0 1.0 Croylisplimtsz v r arey 1.0 1.0 1.0 1.0 0.32 At the present tlme there is no satisfactory Buckwheat." 1.0 1.0 032 0.1 0.1 herbicide for applying to the weeds in rows of fgf flg growing vegetables such as potatoes, carrots, Euonymus 0 1 j i j cabbage, beans and the like where it is necessary 28 -g to follow'one crop with another. The compounds 1j 1 1 j 0:32 produce rapid killing of weeds and when sprayed between the rows of vegetables do not impart any 312 312 312 110 110 objectionable taste to vegetables. Another 1m- 23 93 03 portant feature is that the compositions of. the 1 1 j j invention exhibit no objectionable residual effect in the soil. In fact, seeds can be planted the 1 Consideredtolemm day after spraying the soil. g l a asal 1-0; sprayed. it b d The compounds may be applied in such conrm ea Spotimg, 1108 Mon 11 sorstems- Peach completely defoliated at 3.2 ercent with no t 1 centratlons as to effect a mere f l n to or buds. At 1.0 percent partial (101011111011 (older M525 TABLE III Results obtained by applying chloroacetic acid (CHzC'ZC'OOH) to the soil of tomato plants growing in four-inch pots. Three plants to each treatment N0. cc. per 4 Pot Mg./ Percent No. Mg/ Percent No. Mg./ Percent No.

-P0t Kill Days Pot Kill Days Pot Kill Days 1 plant dea 01 application.

d, 2 plants basal collapse in 6 days at 32 mg. per 4 pct rate 5 6 The following species were not injured when We claim: CI-IzClCOOH was applied to the soil at the rate The plant regulant composition for killing of 32 mg. per 4" pot: plants comprising chloroacetic acid in an amount Lawn grasses varying from 0.3% to 10% and undecylenic acid Corn 5 in an amount varying from 0.3% to 10%. Barley PERCY W. ZIMMERMAMN. Sorghum ALBERT E. HITCHCOCK.

TABLE IV Responses induced by applying chloroacetic acid [C'HzCZCOOH (CZA)] and undecylem'c acid (UN) alone and in mixtures as a foliage spray Tomato Chickwced Buckwheat Treatment 24 hours toxicity Killing 24 hours toxicity Killing 24 hours toxicity Killing Foliage Stem F l Stem Per- Foliage Stem 1:31; as

Dead- Collapse.

do UN 0.32 0 O---- 01A .32 UN .32 Dead ..(10 3 6 CIA .32 UN 1.0. Dead 1 3 CIA 1.0 UN .32. Collapse 1 1 CIA 1.0 UN 1.0. Dead"... 1 1

1 Foliage:

+ +=95% foliage killed. +*+=75-90% foliage killed. 50-60% foliage killed. 25% foliage killed.

2 Stem:

+ +==80% stems collapsed. +=50% stem collapsed. ++=25% stems collapsed.

REFERENCES CITED The following references are of record. in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,282,732 Lean May 12, 1942 OTHER REFERENCES The Chemistry and Uses of Insecticides, de Ong (1948), pages 173 and 174.

Chemical Abstracts, vol. 42, 001. 3803H (194 abstract of article by Brodersen et a1. 

